menu, customization of food for allergies or preferences, and the physical requirement to bring food to the table, make the transaction more clumsy.

Grocery stores jumped on self-service about 15 years ago, and at first it seemed like a success, with over 22% of transactions going through self-service in 2008. By 2011 supermarkets were actually ripping out self-service kiosks because revenue and transactions were down. Their success has been up and down and affected by region ever since.

In fact, self-service in general is getting worse rather than better. A 2011 study by the Technology Services Industry Association showed that in 2003, 48% of self-service transactions were considered a "success," a success being when the customer believes he has gotten the information or the action out of the transaction that he wanted. The number reached an all-time low in 2011 at 39%. Granted, mobile phones are changing the equation, and the TSIA has not updated the number, but self-service is increasing, and there's not a lot of evidence out there supporting the idea that we're getting better at it for customers.

Think about that for a moment: The technology of 2003 was easier for people to handle than that of 2011. There's no good reason for this to be so with a decade of improvements in UX, interconnectedness, big data, artificial intelligence, and all sorts of other areas. What's going wrong?

For one, there's a natural reality that the more complex the transaction we are attempting, the more likely it is to fail. We hit all the low-hanging fruit, so naturally it is going to get harder.

For another, customers are expecting more from each transaction. They have a decade more of experience with technology. They know what it can do. They have phones in their hands that link them to the world. So expectations have grown from, "I got my boarding pass." If restaurants want to put these kiosks in place they'd be smart to follow a few rules. They are:

Keep it simple. So easy to say, so hard to remember. Starbucks' pay-by-phone app is popular because it is easy, and it does just a few discrete things. Restaurants need to resist the urge to pile on capabilities, advertising, or other distractions.

Keep your people. Not all of them, but more of them than you want. Not only do they need to be there when the thing doesn't work, but what's the difference between the airport and the grocery store? The final step of the airport check-in is taking your ID or bags to a person. The grocery self-checkout requires no people and when things go wrong, help might be far away.

Keep it up-to-date. The shiny new tablets on the table look great. How long before they are covered in cheese, are running old operating systems, and aren't compatible with your new back-office inventory management system? Committing to self-service means a commitment to keeping current. If you can't do it, don't start.

Keep it mobile. One way to avoid the problem with old terminals is to not use terminals at all. Ditching the tablets attached to table for a mobile app (again, like Starbucks) means you aren't on the hook for physically maintaining the kiosks.

Too many companies treat digital and mobile strategies as pet projects. Here are four ideas to shake up your company. Also in the Digital Disruption issue of InformationWeek: Six enduring truths about selecting enterprise software. (Free registration required.)